The present invention relates generally to an ignition distributor breaker contact point set and, more particularly, to a breaker point set which produces a minimal amount of radio frequency interference and which is less subject to pre-mature failure than low radio frequency interference breaker point sets heretofore employed.
It has been discovered that a particular type of radio frequency interference is inherently generated by most distributor breaker contact point sets. This is principally due to the fact that during operation, arcing is occasionally experienced between the contacts thus providing a path for the discharge of the energy stored in the condensor. It is this discharge which results in a "popping" or "cracking" type of radio frequency interference. This problem is particularly acute in breaker point sets in which the condensor is connected to the contact spring and contact arm by a circular lead which, in fact, functions as a rather effective radiating antenna.
The problem of radio frequency interference was minimized by breaker point sets which position the condensor in electrical contact with a slotted conductive tab member to which is secured a breaker contact. Such a breaker point set is described in U.S. Pat. No. 3,646,301 which issued on Feb. 29, 1972 to Gerald O. Hutzinger et al. The breaker point set disclosed in the Hutzinger et al. patent employs an elongated strip of electrically conductive material connecting the breaker arm to the electrically conductive post of the condensor. The contact points engage one another through a longitudinally extending slot in this strip which is positioned parallel to the breaker arm. While this design effectively minimizes radio frequency interference, due to its provision of a direct outlet for the discharge current from the condensor in the event of arcing between the contact points and its providing loops of minimal area and of opposite polarity, the breaker point set presents certain inherent design disadvantages. For example, the provision of having the contact points engage and disengage through a longitudinal slot in the strip of electrically conductive material may result in premature failure should the strip become displaced and thus result in the shorting out of the contacts. Additionally, the positioning of the elongated strip substantially parallel to the breaker arm fails to provide sufficient support for the breaker point set and, in particular, the condensor.
Against the foregoing background, it is a primary objective of the present invention to provide an ignition distributor breaker contact point set which minimizes radio frequency interference and which is resistant to premature failure due to shorting out of the contacts.
It is another object of the present invention to provide an ignition distributor breaker contact point set which provides adequate support for the condensor.